The type of wildlife they claim to have encountered does not exist in the Gobi. They trekked across Mongolia without food for weeks and without water for days. They crossed the Himalayas with no real warm clothes, and no climbing gear, or maps. The author never even bothered to learn the first name of his American friend (Smith) let alone his life story, and this is on a 3000 mile journey where they are constantly dependent on one-antoher. None of his companions were ever located, or found on military records.
I don't doubt that there were amazing escapes, but this is one where the nugget of truth is coated in a thick batter of deep-fried exageration. Check out various reviews and records for more precise geographic and biological discrepencies.
http://outside.away.com/outside/features/200301/200301_adventure_canon_9.html